Switch



July 28, 1942. w. M. s. KILGOUR SWITCH Filed Nov. 15, 1940 "Wail 02' 129010;".

Patented July 28, 1942 "U N l T E D STAT E 5 RATE NT PF! C E SWITCH Walter M. S. Kilgour, Lexington, Mass.

Application November 13, 1940, Serial No.'-36 5,546

(Cl. ZOO-52) 16 Claims.

My invention; relatesto switches operated by shock, switches accordingto the invention being particularly adapted for use as collision switches for vehiclesv drivenby internal combustion engines.

The invention will :be bestunderstood from the following descriptionwhen; read in the light of the accompanying drawing :of several embodiments-of the invention,- the'scope of the invention 'beingmore particularly pointed out in the appended claims.

-In the drawing Fig. 17 is anelevation of a'switch according to the invention;

.Fig.jj2 is a section'on:the.:line22 of Fig. 1;

-Fig. 3; is' a: sectionion the line 3-3 of Fig. 2;

:Fig. 4 shows the switchaccordingjtof Figs. 1, 2

and-:3 in a different operative position; i and Fig 5, isa'section corresponding, to Fig. 2 showing a modifiedformof switch according tothe invention.

"Pteferringparticularly-to the modification of the invention illustrated'by Figs. 1 to 4,the

switch includes.a'lowerportion l, of Bakelite or other suitable insulating material, preferably moulded tov the shape shown. This lower portion at its uppergside is recessed :to'form an axially positioned well 3 and an gupwardly extending peripheral annular; side wall'5. The recess adjacent the sidewall-5 provides an annular flat surface 1, and: connecting this surface with the side wall portionsofithe well is a frusto-conical surface 9.

On the-bottom of the above, described recess of the lower portion l'of the switch is'a cup-shaped sheet metal contact member; preferably of steel, conforming to the surfaces land 9 and those of the well 3 so that-the contact-member forms a cup or well having'anupwardlyand outwardly flaring rim I3. Welded or'otherwise united to the under side of ,the bottom of the well portion II of the contact member is a metallic terminal stud l5 which extends through an opening [6 in the portion to the exterior of thatportion.

To the terminal stud |5 may be connected a bracket I! by means of a nut l9 screw-threaded on the. terminal stud. This bracket may be rigidly secured by a bolt 2| to the chassis frame 23 of a vehicle so that the above described cup-shaped contact will be grounded to that frame.

Above the side wall 5 of the lower portion of the switch is shown a sleeve-like member 25 having a downwardly projecting portion 21 surrounding the lower portion of the switch. At its exformed of a light weight, relativelysoft metal such as aluminum, is spun or forced over a corresponding shoulder onthe under side of the portion l, as indicated at-29, so as to hold'the sleeve and portion I in assembled relation.

As illustrated, the sleeve-25 has an internal, inwardly projecting flange: 3| which-at its upper side at-its inner edge is recessed to provide an annular groove 33. Inwardly of the flange 3| is a sleeve '35 having'at its upper edge an outwardly projecting flange 31,- the outer edge of this latter flange being formed with a thinner portion 39 received by-the groove-33-of the flange :3|. The sleeve 35 preferably is of steel, while: the sleeve 25, as above mentioned, preferably is of aluminum. In forming the-device the sleeve 5; preferably is cast about the sleeve 35-which-causes the contacting surfaces of the groove 33 of the sleeve 25 and the portion 39 of'the sleeve'35 to unite in such way that the sleeves 25- and 35 are integrally joined.

At its lowerend the sleeve 3531s formed to provide a' frusto-conical portion 4| in slightly spaced relation toithe upwardly and outwardly'flaring rim l3 of the cup-shaped-contact so=as to provide a passage 43 (Fig. 4) between the endof the sleeve 35*andthisrim, which passage with respect to mercury is somewhatrestricted.

As 'shown,- the sleeve 35 is provided with an axial bore 45'which reciprocally receives a plunger 4Tof insulating material such-as Bakelite. At its upper end the plunger is formedintegrally with a head 49. Beneath this head is a coiled'compression spring 5| which at its upper end bears against the under side ofthe head 49 and at its lower-end against the bottom surface -53-of an enlargement 55 at the upperend-portion of the bore 45 of the sleeve =35 so that the spring urges the plunger to move upwardly. As shown, the

plunger is-provided witha deep recess 51 opening on the-upper-side of e the head 49. Received by this opening is a rod or strutr59 the lower end of which bears against the bottom of the recess while its upper end bearsagainsta normally fixed cap 6| at the upper side of'the-switchso that the plunger is normally held in the position shown by Fig. 1, in which position the lower-end of the plunger projects into the well or cup ll of the contact member hereinbefore described.

In the well I provided by the cup-shaped contact is abody-63 of conductive liquid such as a globule of mercury. The plunger-actseas a displacement-member for the mercury, and when the partsare in the position shown byFig. 1

treme lower; end this sleeve, which preferably is 5 causes the mercuryzto contact the end portion 4| of the sleeve 35 and place that sleeve in electrical communication with the cup-shaped contact beneath it. When the plunger 41 is raised to its position shown by Fig. 4 the level of the body of mercury will drop so that the mercury will flow out of the restricted passage 43 and thus will be out of contact with the portion 4| of the sleeve 35 and interrupt communication between the sleeve and the cup-shaped contact.

In the present embodiment of the invention a metallic spring clamp 65 extends about the extension 21 of the sleeve 25, being clamped thereto by the bolt 61 which extends through the ears 69 at the opposite ends of the clamp. To the clamp 65 may be brazed the foot I of a projecting metallic lug II. To this lug may be se cured a terminal lug I2 by means of a bolt I3, the terminal lug 12 being at the end of the ground wire I4 of the battery of an internal combustion engine driven vehicle. With the parts in the position shown by Fig. 1 the battery is grounded to the chassis of the vehicle; but when the parts are in the position shown by Fig. 4 this ground connection is interrupted and the battery no longer can supply energy to the wiring system of the vehicle.

As illustrated, the sleeve 25 at its upper end carries a cover of insulating material comprising an upwardly extending sleeve I5. This sleeve at its upper end has an inwardly extending, annular flange 'I'I forming an opening I9, there being an annular, upwardly projecting flange 8I about the edge of this opening. Carried by the flange BI is the cap 6| hereinbefore mentioned, the cap having a circumferential flange 82 removably fitting over the flange 8|, the cap further having an axially positioned, downwardly projecting portion 83 surrounded by an annular groove 85. This projecting portion 83 at its lower end is provided with a shallow recess 81 for receiving the upper end of the strut 59.

For holding the cover comprising the sleeve I and the cap 6| in assembled relation with each other and with the remainder of the device the sleeve 25 is provided at diametrically opposite portions with projecting pivots 89 on which are mounted the opposite ends of a bail 9| of spring material, the cap at its upper side being provided with a groove 93 for detachably receiving this bail. By springing the bail out of the groove 93 it may be turned on its pivot to release the cap GI and permit it to be removed.

As shown, the strut 59 is provided with a weight 95 so that when the vehicle carrying the switch collides with an object the upper end of the strut will snap out of the recess 81, in which it is resiliently held by the spring 5|, and enter the groove 85 to permit this spring to move the plunger 41 into its position shown by Fig. 4. In this position the upper end of the strut is above the upper end of the annular flange 8| at the top of the switch so that upon removal of the cap with the parts in the position shown by Fig. 4 the switch readily may be reset to position the parts as shown in Fig. 1.

As illustrated, internally fitting the annular wall 5 of the lower portion I of the switch is a sleeve 91 of insulating material. This sleeve at its upper end has an inwardly projecting flange 99 which at its inner edge has a downwardly extending sleeve IOI surrounding the metallic sleeve 35. In this way an annular chamber I03 with walls of insulating material is formed about the sleeve 35, this chamber communicating with the passage 43. As a result of this construction,

if the collision causes tilting or upsetting of the vehicle the globule of mercury, because of its high surface tension and the somewhat restricted nature of the passage 43, will flow as a body through that passage into the annular chamber I03 where it cannot establish the connection of the ground wire of the battery to the chassis even though the plunger 41 should fail to withdraw from the well I I.

As shown in Figs. 1 and 2, the upper end of the head 49 of the plunger 41 fixedly carries an annular plate I05 above which are placed yielding spring contacts I01 and I09 secured to the insulating sleeve 15 by binding screws III and H3 respectively. The contacts I01 and I09 at their lower ends have inturned portions H5 in position to be contacted by the plate I05 when the parts are in the position shown by Fig. 4.

In practice the binding screw II3 may be con nected by a lead I H to the bracket H for grounding the contact I09. The binding screw III may be connected to a conductor II9 which leads to such terminal of the vehicle charging generator cut-out switch that upon grounding of that terminal the generator will be rendered inoperative to supply energy to the vehicle winding. This terminal of the cut-out switch will be grounded when the parts are in the position shown by Fig. 4, so that when the parts are in such position not only will the battery be inoperative to supply energy to the wiring system of the vehicle but the vehicle generator will be rendered inoperative to supply energy to the winding.

In the modification shown by Fig. 5 the parts are the same as in the modification shown by Figs. 1 to 4 except that instead of the contacts I01 and I09 of the switch according to Figs. 1 to 4 longer spring contacts I2I and I23 are provided. These longer contacts have portions I25 normally in contact with the annular metal plate I05 carried by the head 49 of the plunger 41, and have terminal portions I 21 normally in contact with the fixed metal ring I29, the latter being insulated from the sleeve 25 by the insulating ring I3I and from the flange 3I by the washerlike insulating plate I33. In this way the conductor II9 will be normally grounded and the ground will be interrupted when a collision occurs. A switch according to Fig. 5 may be employed in connection with vehicles having magneto generators, or in connection with other wiring systems where the vehicle generator, or its control or cut-out switch, has a terminal or contact normally connected to ground and the generator is rendered inoperative to supply energy to the wiring system upon interrupting such ground connection.

It will be understood that, within the scope of the appended claims, wide deviations may be made from the forms of the invention herein described without departing from the spirit of the invention.

I claim:

1. A switch having, in combination, means forming a container, a body of mercury in said container, means presenting an annular, outwardly and upwardly flaring surface about the upper opening of said container, means presenting a second annular surface above the first mentioned surface, said surfaces each comprising conductive material, and a reciprocal plunger in said container for causing said mercury to flow into and recede from the space between said surfaces for establishing and interrupting electrical communication between the conductive materials of said surfaces.

2. A switch having, in combination, --a container, a body of mercury in said container, a

part above said body in slightly spaced relation to the walls of said container toprovide a relatively restricted passage therebetween, and a plunger extending through said part for raising and lowering the level of the mercury to cause it to move into and out of contact with said part.

3. A switch having, in combination, a container, a body of mercury in said container, a part above said body in slightly spaced relation to the walls of said container to provide a relatively restricted passage therebetween, a plunger extending through said part for raising and lowering the level of the mercury to cause it to move into and out of contact with said part, and a chamber in communication with said container into which said body of mercury may flow upon tilting of said switch.

4. A switch according to claim. 3 in which the part above the body of mercury is so shaped and so spaced from the walls of said container as to provide an annular, restricted passage, the chamber into which the mercury may discharge extending entirely around said passage so that the mercury may flow into it when the switch is tilted in any direction.

5. A switch having, in combination, a container, a body of mercury in said container, a part above said body in slightly spaced relation to the walls of said container to provide a relatively restricted passage therebetween, a reciprocal plunger extending through said part for raising and lowering the level of the mercury to cause it to move into and out of contact with said part, shock operated means for moving said plunger for causing said body to move out of contact with said part.

6. A switch having, in combination, a container, a body of mercury in said container, a part above said body in slightly spaced relation to the walls of said container to provide a relatively restricted passage therebetween, a reciprocal plunger extending through said part for raising and lowering the level of the mercury to cause it to move into and out of contact with said part, spring means urging said plunger away from said body, and a shock operated trigger means for releasing said plunger to permit said spring means to move it.

7. A switch having, in combination, a container having an upwardly and outwardly flaring rim, a body of mercury in said container, a part above said rim and the opening of said container in slightly spaced relation to said rim en tirely around it, said container and part comprising surface portions of conductive material, a chamber about said part into which said body may discharge through the space between said part and rim upon tilting of the switch in any direction, a reciprocal plunger extending through said part into said container, spring means urging aid plunger away from said body, and a shock operated trigger means for releasing said plunger to permit said spring means to move it,

8. A switch having, in combination, means presenting a container for a body of mercury and a pair of contacts to be placed in and out of electrical communication by said body, displacement means for said body for raising and lowering its level for causing it to establish and interrupt such communication, an auxiliary switch means,

and-shock operated means for causing said displacement means to lower the level of said body for interrupting such communication and for actuating said auxiliaryswitch means.

9. A switch having, in combination, means presenting a container for a body of mercury and a pair of contacts to be placed in and out of electrical communication by said body, displacement means for said body for raising and lowering its level for causing it to establish and interrupt such communication, an auxiliary switch means controlled by said displacement means, and shock operated means for causing said displacement means to lower the level of said body for interrupting electrical communication between said contacts and to actuate said auxiliary switch means.

10. A switch having, in combination, means presenting a container for a body of mercury and a pair of contacts to be placed in and out of electrical communication by said body, a reciprocal plunger for raising and lowering the level of said body for causing the latter to establish and interrupt such communication, an auxiliary switch means operated by movement of said plunger, and shock operated means for causing movement of said plunger.

11. A switch having, in combination, a container, a body of mercury in said container, a part above said body in slightly spaced relation to the walls of said container, a plunger extending through said part for raising and lowering the level of the mercury to cause it to move into and out of contact with said part, an auxiliar switch means controlled by movement of said plunger, a spring means for urging said plunger away from said body, and shock operated means for releasing said plunger for permitting said spring means to move it.

12. A switch having means presenting a container for a body of mercury and a pair of contacts to be placed in and out of electrical communication by said body, a plunger for raising and lowering the level of said body for establishing and interrupting such communication, a spring means for urging said plunger toward a fixed part of said switch, and a shock releasable strut between said plunger and fixed part normally preventing movement of said plunger.

13. A switch having means presenting a container for a body of mercury and a pair of contacts to be placed in and out of electrical communication by said body, a plunger for raising and lowering the level of said body for establishing and interrupting such communication, a spring means for urging said plunger toward a fixed part of said switch, a shock releasable strut between said plunger and fixed part normally preventing movement of said plunger, and an auxiliary switch adapted to be actuated by said plunger when said strut is released.

14. A switch having, in combination, a container for a body of mercury, means forming an electrode having a downwardly facing annular surface of material area above said body in normally insulated relation thereto, and a vertically reciprocal plunger surrounded by said downwardly facing electrode surface for raising and lowering the upper surface of said body into and out of contact with said downwardly facing electrode surface.

15. A switch having, in combination, a con tainer for a body of mercury, which container has an outwardly and upwardly flaring rim, means forming a downwardly facing surface above said rim in slightly spaced relation thereto to pro- 16. A switch according to claim 15 in which vide a restricted passage therebetween, a portion the rim of the container and the downwardly at least of said surface constituting an electrode, facing surface and the portion of the latter which and a reciprocal plunger for raising and lowering constitutes the electrode all are annular and surthe level of said body to cause it to flow in said 5 round the plunger.

restricted passage into and out of contact with said electrode. WALTER M. S. KILGOUR. 

